1. Field of the Invention
The present invention relates to techniques for displaying content on a computer display. More specifically, the present invention relates to a method and apparatus for displaying and browsing through a sparse view of content items in a hierarchy.
2. Related Art
When content, such as text or graphics, is displayed in a window, the content frequently requires more display space than is available in the window. Often, content items are organized hierarchically, to allow a user to more easily understand and browse through the content items to find a desired item.
One technique commonly used to visualize hierarchical structures is the “folder view,” which, for example, is provided by Microsoft® Windows™ File Explorer. The folder view (also known as a “tree view”) displays the hierarchy using a tree control, in which a node that is selected by a user expands to reveal the node's sub-nodes, if they exist. However, browsing a large amount of data using a tree control can be tedious. As the data set grows, the user has to browse through a growing vertical set of nodes. This involves rendering a larger amount of data, which can result in substantial performance degradation. For instance, in a web-based tree control, rendering the tree can involve retrieving the data from a remote location, rendering the tree to HTML at another location, and then sending the output to a client browser. Performing these operations can significantly decrease performance.
Hence, what is needed is a method and an apparatus for displaying and browsing through content items in a hierarchy, without the limitations of existing systems.